Shellfish Safety Notification: Sport-Harvested Bivalve Shellfish from Mendocino County

Date: September 7, 2023
Number: SN23-009
Contact: CDPHpress@cdph.ca.gov​​

Dangerous levels of paralytic shellfish poisoning (PSP) toxins have been detected in mussels from ​Mendocino County. The naturally occurring PSP toxins can cause illness or death in humans. Cooking does not destroy the toxin.

The California Depart​ment of Public Health (CDPH) is advising consumers not to eat sport-harvested mussels, clams, or scallops from Mendocino County. 

This shellfish sa​​fety notification is in addition to the annual mussel quarantine. The annual quarantine applies to all species of mussels harvested for human consumption along the California coast, as well as all bays and estuaries, and will continue through at least October 31.

This warni​​ng does not apply to commercially sold clams, mussels, scallops, or oysters from approved sources. State law permits only state-certified commercial shellfish harvesters or dealers to sell these products. Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing to monitor for toxins.

PSP toxins affect the central nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eatin​​g toxic shellfish. These symptoms are typically followed by loss of balance, lack of muscular coordination, slurred speech, and difficulty swallowing. In severe poisonings, complete muscular paralysis and death from asphyxiation can occur.